Uranium marbles: "Nothing says Merry Christmas like a little bit of radiation," says Richard-1971294. He'd love to get his hands on some uranium marbles. Back in the old days, pigments containing uranium oxide were used in lots of items, including ceramic glazes, green-tinted glassware and, yes, children's marbles. Black Light World, which sells a three-pack of uranium-doped marbles for $9.95, says they're "totally safe" — even though radioactive caution stickers are plastered all over the promotional images. You can also find 'em on eBay.

Dinosaur Corporation

A carnotaurus skull is flanked by a scale replica, available from the Dinosaur Corporation.

Dinosaur skulls: "Dino skull replicas are cool and geeky!" David Flowers tweeted in his response to the call for entries. The Dinosaur Corporation offers a wide selection of skulls, molded out of polyurethane resin to look like the real thing ... only smaller. If you're looking for a real dinosaur skull, that'll cost you. A T. rex skull sold for $215,000 in March (and some dino dung went for $1,200). Flowers also put a naked mole rat plushie on his geek-gift wish list.

The Elements Vault: "Physics is hot these days, but for lovers of chemistry, this kit from Theodore Gray will be a real treat." says KGill. "His gorgeous book about the elements, 'The Elements: A Visual Exploration of Every Known Atom in the Universe,' showcased the elegance of the periodic table, and the beauty of the elements. This collection incudes new text and photographs, reproductions of historic documents, a pop-up model of an atom, and samples of several elements."

USB microscope: "A USB microscope, with the ability to capture images digitally, is a great geek gift!" says Paliniasky. There's a mind-boggling selection, ranging from less than $20 to astronomical prices.

Plush microbes: "GiantMicrobes are way awesome and super cute — stuffed animal versions of microorganisms," says biology student Kelsey Plesniak, a member of the Cosmic Log corps on Facebook. As we head into flu season, what better gift could you give a microbiology geek than ... a cuddly flu bug?

Wi-Fi detector shirt:This $14.99 ThinkGeek T-shirt has a decal that glows to indicate the signal strength of wireless networks in the area. "My son the math teacher bought one of these earlier this year," George Buddy Dow says on Facebook. "Inexpensive and practical." Just don't forget to remove the decal and the battery pack before you put it in the wash. Dow also puts in a plug for the "Ant Farm Revolution," which sounds like an entomological Occupy movement.

ThinkGeek

Cut a slice with the starship Enterprise.

Star Trek pizza cutter: Joel Davis casts his vote for a $29.99 ThinkGeek kitchen accessory that promises to "boldly cut pizza where no man has cut before." It's as if you're holding a miniaturized starship Enterprise in the palm of your hand. Come to think of it, I've seen that episode.

Pi plate: "A pi plate is available. To make pies in," Jan Smith writes. "Has a large pi symbol in the center and the numbers 3.14159... etc., all around the edge of the plate. I got one for my son." Here's an alternate design for the pi plate. Any way you slice it, this will be a good kitchen item to have around for March 14 ... Pi Day.

Extra credit: You'll find all sorts of geeky (and not-so-geeky) gift ideas by following the links below, and you'll also want to check out our holiday book roundup. You might also consider supporting The Illuminated Origin of Species, an effort by artist/naturalist Kelly Houle to create an illuminated manuscript of Charles Darwin's masterwork in the spirit of the Book of Kells. To support the effort, Houle is offering sets of Darwin-themed greeting cards, beetle prints and an adopt-a-beetle program.

Don't forget to cast a vote for your favorite gift among the top 10, and may the best geek win!

Update for 4:45 p.m. ET Nov. 23: Thanks so much for your votes. Looks like it could be a close contest. The top Science Geek Gift of 2011 will be selected based on the tally as of noon ET Sunday, and announced in a follow-up item on Monday.